package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.print.DocFlavor;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

//检查用户是否已经完成登录
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER=new AntPathMatcher();
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request=(HttpServletRequest) servletRequest;
        HttpServletResponse response=(HttpServletResponse) servletResponse;
        //1.获取本次请求的URI
        String requestURI = request.getRequestURI();

        log.info("拦截到请求:{}",requestURI);
        //定义不需要处理的请求路径
        String[] urls=new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login"
        };
        //2.判断本次请求是否需要处理
        boolean check=check(urls,requestURI);
        //3.如果不需要处理，则直接放行
        if(check)
        {
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }
        //4.判断后端用户是否已经登录
        if (request.getSession().getAttribute("employee")!=null)
        {
            log.info("用户已经登录,用户id为:{}",request.getSession().getAttribute("employee"));
            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);
            filterChain.doFilter(request,response);
            return;
        }
        //4.2.判断用户是否已经登录
        if (request.getSession().getAttribute("user")!=null)
        {
            log.info("用户已经登录,用户id为:{}",request.getSession().getAttribute("user"));
            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);
            filterChain.doFilter(request,response);
            return;
        }
        log.info("用户未登录");
        //5.如果未登录则返回登录结果
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }
    //路径匹配，检查是否放行
    public boolean check(String[] urls,String requestURI)
    {
        for(String url:urls){
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match){
                return true;
            }
        }
     return false;
    }
}
